The Cornell university NT cluster is the only case I have heard of
that was designed to perform calculations like a Beowulf cluster.
I believe to recollect its cost was $3M for 256 procs, not really
cheap.
Note that it is trivial to dual boot on such a cluster, on official
days it can be the preferred OS of the sponsoring company, the rest
of the time the most reliable free OS of your choice.
Would you refuse $3M knowing this?
Dan